The goal of this Phase I project is to prepare antibodies against quinolinic acid and perform some initial experiments to determine the specificity of an assay for quinolinic acid based on these antibodies. The Phase I effort will provide an important component of the assay and a clear direction of experimentation to be carried out in the Phase II of this project. The measurement of quinolinic acid in body fluids may prove to be an important marker for diagnosing the development of AIDS dementia.